The interpretation timeline
Jeremiah 26:3 Douay-Rheims

If so be they will hearken and be converted every one from his evil way; that I may repent me of the evil that I think to do unto them for the wickedness of their doings.

A.D. 397 – 1871 5 witnesses

Patristic

before A.D. 750
397
A.D.
Ambrose of Milan Patristic
A.D. 339–397
“The Novatians bring up a question from the words of the apostle Peter. Because he said, "if perhaps," they think that he did not imply that forgiveness would be granted on repentance. But let them consider concerning to whom the words were spoken—of Simon, who did not believe through faith but was contemplating trickery. So, too, the Lord, to him who said, "Lord, I will follow you wherever you go," replied, "Foxes have holes." For he knew that the man was not being fully sincere. If, then, the Lord refused to him who was not baptized permission to follow him, because he saw that he was not sincere, do you wonder that the apostle did not absolve him who after baptism was guilty of deceit and whom he declared to be still in the bond of iniquity? But let this be my answer to them. As to myself, I say that Peter did not doubt, and I do not think that so great a question can be so easily disposed of by the questionable interpretation of a single word. For if they think that Peter doubted, did God doubt, who said to the prophet Jeremiah, "Stand in the court of the Lord's house, and you shall give an answer to all Judah, to those who have come to worship in the Lord's house, even all the words that I have appointed for you to answer to them. Do not omit a word, perhaps they will listen and be converted." Let them say, then, that God also did not know what would happen. But ignorance is not implied in that word, but the common custom of Holy Scripture is observed to be taken in its simplest sense. Inasmuch as the Lord says also to Ezekiel, "Son of man, I will send you to the house of Israel, to those who have angered me, both themselves and their ancestors, this very day, and you shall say to them, Thus says the Lord, if perhaps they will hear and be afraid." Did God not know that they could or could not be converted? So, then, that expression is not always a proof of doubt.”
Source
435
A.D.
John Cassian Patristic
c. A.D. 360–435
“But if one says that God revoked that severe sentence in consideration of their penitence, according to what he says by Ezekiel, "If I say to the wicked, 'You will surely die' and he becomes penitent for his sin and does judgment and justice … he shall surely live; he shall not die," we are similarly taught that we should not be obstinate in our resolve, but that we should with gentle pity soften down the threats that necessity called forth. That we may not conclude that the Lord granted this specially to the Ninevites, he continually affirms by Jeremiah that he will do the same in general toward all and promises that without delay he will change his sentence in accordance with what we deserve, saying, "I will suddenly speak against a nation and against a kingdom to root out and to pull down and to destroy it. If that nation repents of the evil which I have spoken against it, I also will repent of the evil which I thought to do to them. And I will suddenly speak of a nation and a kingdom, to build up and to plant it. If it shall do evil in My sight, that it obey not my voice: I will repent of the good that I thought to do to it." To Ezekiel also: "Leave out not a word, if so they will hearken and be converted every one from his evil way that I may repent of the evil that I thought to do to them for the wickedness of their doings." And by these passages it is declared that we ought not obstinately to stick to our decisions but to modify them with reason and judgment, and that better courses should always be adopted and preferred and that we should turn without any delay to that course that is considered the more profitable. For this above all that invaluable sentence teaches us, because though each person's end is known beforehand to God before his birth, yet somehow God so orders all things by a plan and method for all, and with regard to human disposition, that he decides on everything not by the mere exercise of his power or according to the indescribable knowledge that his foreknowledge possesses but according to the people's present actions, and he rejects or draws to himself each one, and daily he either grants or withholds his grace.”
Source

Scholastic

c. 1100 – 1500
1252
A.D.
Thomas Aquinas Catholic
1225–1274
“Here the prophecy is set down: and it is divided into three parts. In the first is set down the occasion of the persecution; in the second is set down the persecution, there, "and the priests heard," etc.; in the third is set down the deliverance, there, "and the princes heard," etc. Now the occasion was from the preaching: hence first he designates the place of the preaching: "stand in the court." Above, 7: "stand in the gate of the house of the Lord, and preach there all the words." Secondly, as to the fruit of amendment: "do not withhold a word"; as to the amendment of guilt, "and let him be converted"; and as to the remission of punishment, "and let it repent." Above, 18: "if that nation shall do penance for its evil, for which I have spoken against it, I also will repent of the evils which I thought to do to it." Thirdly, he sets down the word of the preaching, "and you shall say." Above, 7: "I will do to this house, in which my name has been called upon, and in which you have trust, and to the place which I gave to you, and to your fathers, as I did to Shiloh: and I will cast you out from my face, as I cast out all your brothers, the whole seed of Ephraim."”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“If so be they will hearken,.... And obey; which is expressive not of ignorance and conjecture in God, but of his patience and long suffering, granting space and time for repentance, and the means of it; which disregarded, leave without excuse: and turn every man from his evil way; his series and course of life, which was evil, and was the case of everyone; so that as their sin was general, the reformation ought to be so too: that I may repent me of the evil which I purpose to do unto them; or "am thinking", or "devising (d) to do unto them"; which repentance must be understood not of a change of mind, but of the course of his providence towards them, which, by his threatenings, and some steps taken, portended ruin and destruction; yet, in case of repentance and reformation, he would change his method of action agreeably to his will: because of the evil of their doings; this was the reason why he had threatened them with the evil of punishment, because of the evil of their actions; which were breaches of his law, and such as provoked the eyes of his glory. (d) "quod ego (sum) cogitans", Schmidt.”
Source
1871
A.D.
1871
“if so be--expressed according to human conceptions; not as if God did not foreknow all contingencies, but to mark the obstinacy of the people and the difficulty of healing them; and to show His own goodness in making the offer which left them without excuse [CALVIN].”
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.